title: Relative contributions of BRCA1 and BRCA2 mutations to "triple-negative" breast cancer in Ashkenazi Women.
abstract: Approximately 10% of Ashkenazi Jewish (AJ) women with breast cancer (BC) carry a founder mutation in BRCA1 or BRCA2. There is an association between BRCA1 mutations and "triple-negative" breast cancer (TNBC) [estrogen receptor (ER) and progesterone receptor (PR) negative, HER2 negative]. We sought to determine the predictive value of the TNBC phenotype for the presence of a BRCA mutation in AJ women ascertained without respect to family history. DNA samples were collected between 8/2000 and 6/2004 from a prevalent cohort of unselected AJ women with breast cancer (median age at diagnosis 56 years). Samples (n = 451) were genotyped for AJ founder mutations. 352 (78.0%) cancers were ER positive, 254 (56.3%) PR positive, and 91 (20.2%) ER negative/PR negative. 63 (14.0%) cancers were HER2 positive (immunohistochemistry 3+ or FISH >2.2). TNBC was observed in 64 patients (14.2%). Founder mutations were detected in 48 samples (10.6%) including 25/64 TNBC (39.1%; 19 BRCA1, 6 BRCA2). Among TNBC patients with family history (FH) information, 6/15 (40%) mutations were found in women without breast or ovarian cancer in a close relative. The positive predictive value of TNBC for a BRCA1 mutation was 30% overall, 50% in women diagnosed<50 years, and 14% in women diagnosed ≥50. TNBC was significantly associated with detecting a mutation in either BRCA1 or BRCA2, but only 25/52 (48%) mutation-associated cancers were TNBC. The prevalence of BRCA founder mutations exceeds 50% in subsets of AJ women with TNBC. FH is an imperfect predictor of mutation status in this group. A significant number of mutation-associated TNBC are due to BRCA2.
authors.affiliation: Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
authors.forename: E
authors.initials: E
authors.lastname: Comen
authors.forename: M
authors.initials: M
authors.lastname: Davids
authors.forename: T
authors.initials: T
authors.lastname: Kirchhoff
authors.forename: C
authors.initials: C
authors.lastname: Hudis
authors.forename: K
authors.initials: K
authors.lastname: Offit
authors.forename: M
authors.initials: M
authors.lastname: Robson
mesh_terms: D000328:Adult; D000368:Aged; D019313:BRCA1 Protein / Q000235:genetics*; D024682:BRCA2 Protein / Q000235:genetics*; D001943:Breast Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018703:Founder Effect; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007585:Jews / Q000235:genetics; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D019313:BRCA1 Protein; D024682:BRCA2 Protein; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone